ServiceModel.Grpc 1.23.0

ServiceModel.Grpc

ServiceModel.Grpc enables applications to communicate with gRPC services using a code-first approach (no .proto files), helps to get around limitations of gRPC protocol like "only reference types", "exact one input", "no nulls", "no value-types". Provides exception handling. Helps to migrate existing WCF solution to gRPC with minimum effort.

ServiceModel.Grpc is package with main functionality, basic Grpc.Core.Api extensions and ClientFactory.

Declare a service contract

A service contract is an interface decorated with the ServiceContract attribute. Interface methods decorated with the OperationContract attribute are treated as gRPC operations.

For example, following ICalculator contract with unary Sum operation and client streaming MultiplyBy operation:

[ServiceContract]
public interface ICalculator
{
 [OperationContract]
 Task<long> Sum(long x, int y, int z, CancellationToken token = default);

 [OperationContract]
 ValueTask<(int Multiplier, IAsyncEnumerable<int> Values)> MultiplyBy(IAsyncEnumerable<int> values, int multiplier, CancellationToken token = default);
}

Configure ClientFactory

ClientFactory serves to configure and create instances of gRPC service clients.

IClientFactory defaultClientFactory
 = new ClientFactory(new ServiceModelGrpcClientOptions
 {
 MarshallerFactory = ...
 DefaultCallOptionsFactory = () => ...
 ErrorHandler = ...
 Logger = ...
 ServiceProvider = ...
 Filters = ...
 });

Configure a gRPC channel

A channel represents a long-lived connection to a gRPC service.

Grpc.Net.Client.GrpcChannel from Grpc.Net.Client NuGet package.

ChannelBase channel = GrpcChannel.ForAddress("http://localhost:5000");

Grpc.Core.Channel from Grpc.Core NuGet package.

ChannelBase channel = new Channel("localhost", 5000, ChannelCredentials.Insecure);

Make gRPC calls

A gRPC call is initiated by calling a method on the client. The gRPC client will handle message serialization and addressing the gRPC call to the correct service.

ICalculator calculator = clientFactory.CreateClient<ICalculator>(channel);

// call Sum: sum == 6
var sum = await calculator.Sum(1, 2, 3);

// call MultiplyBy: multiplier == 2, values == [] {2, 4, 6}
var (multiplier, values) = await calculator.MultiplyBy(new[] {1, 2, 3}, 2);

Links

• Documentation
• ServiceModel.Grpc GitHub
• Examples